The life of the drill string is maximized by designing pipe that is resistant to fatigue. Fatigue stress is primarily concentrated in areas where there is a sudden change in geometry. In drill pipe this is the upset area adjacent to the tool joint weld. It consists of a transition from the thin cross-sectional area of the drill pipe body to the thick cross-sectional area of the tool joint. The longer and smoother the manufacturer can make the upset transition area the better it is for resisting stress concentrations. This is done by making the transition zone between the body of the pipe and the tool joint as smooth and gradual as possible.

Using the company’s proprietary forge practices, TSC HDD is able to manufacture an extended internal upset with a shallow run-out angle that blends seamlessly into the pipe body’s internal diameter. This greatly improves the pipe’s performance and helps to ensure it will not fail in this stress prone region. To reduce fatigue even further, TSC HDD also grinds both the internal and external diameters of the assembled pipe adjacent to the weld line.